The Research On Structure Postmortem And Remaining Oil Recovery In Thick Oil Reservoir

In the thick oil reservoir depositing by fluid facies, the character of cycle is quite clear. Because of the existence of interbed, the interior interference is more serious in the special high water-cut stage, it lead to void circulation inside the thick oil reservoir, and makes the development more difficult.After the special high water-cut stage in the Lamadian oil field, the development face the antilogy of"three high and small", such as overall water content is high and the aqueous stratum difference is small in each development series, the usage degree of reservoir is high and water-flushed degree is low inside the thick oil reservoir, the production degree of exploitable reserves is high and the reserve-production balance ration is low. Particularly core intersection and oil reserves is large, meanwhile in-thick layer heterogeneity is serious, for example the layer of remaining oil is relatively concentrated and it's production-injection is no or low avail. So in special high water-cut stage, the need of oil-field adjustment can't be satisfied with the old method of cyclical phase correlation, according to the development condition, we use structure postmortem method inside thick oil reservoir, re-know the law of remaining oil distribution and the exploiting integrated study, by many kinds of method , such as meticulous postmortem method, combination of performance-static behavior and so on, advancing the method of reservoir description, announcing the character of thick layer heterogeneity, studying the in-layer structural unit status and the character of interbed distribution, analyzing the rich zone of remaining oil distribution, and guiding the oil-field overall adjustment.The article includes such topic:Firstly, according to the basis principle of roch layer interface analyzing, and developing structure postmortem method inside thick oil reservoir. Using the cycle character of logging trace,vertical permeability contrast,and the initial explanation of flood out pattern after drilling, tracing and correlate the hierarchical structure interface inside the sand body, completely diving the single layer and intraformational bed inside the thick oil reservoir, defining the principle of intraformational bed and single layer.Secondly, studying the using condition between structure interface up and down inside thick oil reservoir, making clearly the growing of in-layer intraformational bed and permeability contrast, which is the main factor of controlling the in-layer remaining oil and re-knowing the distribution principle of remaining oil inside the layer. For example remaining oil is on the top of structure interface's sand body,in the rhythmic layering of interface sequence and in the rhythmic layering of more high permeability.Thirdly, on the basement of reservoir heterogeneity character and the principle of reservoir changing character, according to different style of sand body character and making different adjustment countermeasure, and by reasonable technology to drill the in-layer remaining oil, which gain better result of controlling water drilling and improve the oil development effect.